The Research On The Typical Characteristics Of Geology Of Kuimeishan Tungsten Deposit,Nanling

The Southern Jiangxi，one of the most enriched tungsten ore-bearing regions thatoccupys the70%of tungsten reserves in China, is confronting the tungsten resources crisis.Especially, for the Kuimeishan tungsten ore deposit in Dingnan, one of the most crucialtungsten ore bodies in Nanling tungsten-tin Metallogenetic deposit zone, the crisis isabsolutely severe nowadays. In order to summarize the metallogenetic mechanism andoffer a better guidance for deep exploration of this orefield, it is imperative to do acombined research.In this dissertation, based on the well-established cognition of geological settings ofmineralization, ore and ore-body structure, ore composition and mineralization stage ofthis orefield, we made a detailed study not only on the crystallography, chemicalcomposition of some common minerals in quartz vein type and skarn type ore and thecorrelations between them. Meanwhile, on the major, trace elements and rare-earthelements of some exposed plutons （viens） that is intimately related with mineralization.The U–Pb ages of the zircon from the granite indicates that the mineralization of thisorefield is mainly relevant to the fine grained biotite granite with the magma crystallizationage of157.7±2.7Ma concealed in the deep area. Geochemical features of trace elementsand rare-earth elements reflect the fact that the hidden biotite granite and its viens are bothderived dominantly from the crust, and the biotite granite generated by crystal fractionationof the primary magmas at the late stage, is rich in volatile, alkali metal and metallogenicelements, providing a enriched source for the formation of the Kuimeishan tungsten oredeposit.Both quartz and wolframite have a similar δ¹⁸O value, which can imply tungsten oredeposit is derived from a same metallogenic hydrotherm system. Furthermore, the QuartzδD－δ18O correlations suggest primitive metallogenic hydrotherm is stemmed from theresidual water in the magmas which would form the biotite granite at the late stage ofcrystal fractionation. The metallogenic hydrotherm of the main mineralization stage,considered to be a hybrid of residual water in the magmas and meteoric water, isincreasingly affected by the meteoric water, as the upwelling of the deep magmatichydrotherm. Spatially, the metallogenic elements may undergo a two stage enrichmentprocess, which is consistent with the fact that there are some new dubious tungsten-bearingveins in the deep area. Re－Os dating for the molybdenite and Ar－Ar dating for the mica coexisting withwolframite revealed that molybdenite and mica have a age of153.7±1.5Ma and155.3±1.6Ma, respectively. Combined with the age of the ore-bearing rock （biotite granite）, all thesegeochronology results revealed that the age of hidden rock and metallogenetic epoch of theKuimeishan tungsten ore deposit are both at the Late Jurassic, mineralization of thisorefield is mainly relevant to the biotite granite concealed in the deep area, and thistungsten ore deposit is a typical product of the peak mineralization stage in response to themassive magmas instrusion events in the Nanling area.